Atran proposes that humans have a unique, innate, domain-specific tendency to create taxonomies of biological kinds. We show that: (1) in ontogenesis, children develop a notion Atran claims to be innate; (2) what Atran claims is unique to biological kinds may be found in artifact kinds; and (3) although Atran proposes a domain-specific mental construct for biological rank, it can be explained in domain- general terms.

We propose that in addition to children's requests for word names being a reflection of an understanding of the referential nature of words, they may also be requests for adult's teaching. These possible requests for teaching among toddlers, along with other indications, suggest that teaching may be a natural cognition that may be related to the development of theory of mind.